(Reuters) – Germany’s Alexander Zverev did his French Open preparations a world of good by beating Chile’s Nicolas Jarry 6-3 3-6 7-6(8) in a grueling, rain-hit final at the Geneva Open on Sunday.

Top seed Zverev, looking for his first title win on clay since clinching the Italian Open last year, had endured a disappointing season so far and had not won a title since the ATP Finals in London in November.

The 22-year-old did not have it easy, taking two hours and 35 minutes to eventually get the better of his unseeded opponent in a match where both players had numerous match points. Two rain delays added to the drama.

Zverev was not as his best with eight double faults punctuating his victory, five of which came in the final set, and he converted only one of 12 break points over the course of the match.

Jarry, who beat Zverev in Barcelona on the same surface in a three-setter last month, fired six aces to Zverev’s three but there was nothing to separate the two players until the third-set tie-break.

With Zverev leading 6-5 in the final set, Jarry battled hard to ensure it went to a tie-breaker. The German then won two points off Jarry’s serve to take a 4-0 lead before Jarry saved three match points.

Zverev double-faulted at 6-6 to nearly hand his Chilean opponent the title but he kept his nerve to eventually win an exciting tie-breaker 10-8.

Zverev, the fifth seed at Roland Garros, takes on Australia’s John Millman in the first round of the French Open on Monday while Jarry starts the tournament against eighth seed and fellow South American Juan Martin del Potro of Argentina.